In search of names
Many Minds
Alright, friends—we’ve come to the end of the 2025 run of Many Minds! Our final episode of the year is an audio essay by yours truly. This is a classic format for the show, one that we only do every so often. Today’s essay is about names. It’s about the question of whether animals have something like names for each other. And it’s also about a deeper question: What even is a name? How do humans use names? How does the historical and ethnographic record kind of complicate our everyday understanding of what names are. I had a lot of fun putting this together, and I do hope you...
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The value of animal cultures
Many Minds
Not long ago culture was considered rare in nature, maybe even uniquely human. But that's changed. We now know that the tree of life is buzzing with culture—and not just on a few lonely branches. Creatures great and small learn songs, migration routes, and feeding techniques from each other. Many species build up reservoirs of knowledge over generations. This has profound implications, not just for our understanding of the natural world, but also for our efforts to protect it. My guest today is . Philippa is an Honorary Lecturer at the University of Exeter, with one foot in science and...
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What is memory for?
Many Minds
Everyone loves a good evolutionary puzzle. Why do we have appendices? Why do we dream? Why do we blush? At first glance, memory would not seem to be in this category. It's clearly useful to remember stuff, after all—to know where to find food, to remember your mistakes so you don't repeat them, to recall who’s friendly and who’s fierce. In fact, though, certain aspects of memory—when you hold them up to the light—turn out to be quite puzzling indeed. My guests today are and . Ali is a philosopher at the London School of Economics (LSE); Johannes is a philosopher at York University,...
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Of breeds and brains
Many Minds
It's hard to say exactly when, but some tens of thousands of years ago, our best friends were born. I'm referring, of course, to dogs. This didn't happen overnight—it was a long process. And it not only changed how those canids behaved and what they looked like, it also changed their brains. As wolves gave way to proto-dogs, and proto-dogs gave way to dingoes and dalmatians and Dobermanns and all the rest, their brains have continued to change. What can we learn from this singular saga? What does it tell us about dogs, about domestication, and about brains? My guest today is . Erin is...
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Monsters and their makers
Many Minds
It seems we've always had monsters among us. We've long been enthralled by dragons and giants, by the likes of Frankenstein and Godzilla and Dracula, by witches and werewolves and countless others. They roam our maps and creation myths; they crop up in our dreams, in our children's books, in our political rhetoric. Where do these beings spring from? What do they do for us? How have they changed over time? And, ultimately, what do our monsters say about their makers? My guests today are and . Both are historians of science and authors of recent books on monsters: Natalie's book is . Surekha's...
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The age of social AI
Many Minds
AI therapists and caregivers. Digital tutors and advisors and friends. Artificial lovers. Griefbots trained to imitate dead loved ones. Welcome, to the bustling world of AI-powered chatbots. This was once the stuff of science fiction, but it's becoming just the stuff of everyday life. What will these systems do to our society, to our relationships, to our social skills and motivations? Are these bots destined to leave us hollowed out, socially stunted, screen-addicted, and wary of good-old-fashioned, in-the-flesh human interaction? Or could they actually be harnessed for good? My guest today...
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Brains of a feather
Many Minds
Birds do the darnedest things. They fly, of course. They sing. They hunt in pitch darkness. They hide their food and remember where they put it. They use tools and migrate over astonishingly vast distances—sometimes even sleeping while in flight. How do they do all this? What's going on in their brains that makes these and other remarkable behaviors possible? How did their evolutionary path mold them into the incredible creatures they are today? My guests today are and . Andrew is a comparative neuroscientist and Associate Professor at the University of Lethbridge in Canada. Georg is a...
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How nature restores the mind
Many Minds
One afternoon you decide to snub your responsibilities and go for a hike. You spend a few hours in the woods or the mountains. You study the bark of trees, you bathe in birdsong, you let your eyes roam along a distant ridgeline. And you come back feeling better, restored somehow—like you have more energy, more patience, more bandwidth. We've all, I'm guessing, had experiences like this. But what's behind these effects? Why would nature restore us? What's the evidence that it really does? And what is even being restored, actually? My guest today is . Marc is an Associate Professor in the...
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From the archive: Revisiting the dawn of human cognition
Many Minds
Hi friends! We're taking a much-needed summer pause—we'll have new episodes for you later in September. In the meanwhile, enjoy this pick from our archives! ------- [originally aired June 1, 2023] There's a common story about the human past that goes something like this. For a few hundred thousand years during the Stone Age we were kind of limping along as a species, in a bit of a cognitive rut, let’s say. But then, quite suddenly, around 30 or 40 thousand years ago in Europe, we really started to come into our own. All of a sudden we became masters of art and ornament, of symbolism and...
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From the archive: Of molecules and memories
Many Minds
Hi friends! We're taking a much-needed August pause—we'll have new episodes for you in September. In the meanwhile, enjoy this pick from our archives! _____ [originally aired February 8, 2024] Where do memories live in the brain? If you've ever taken a neuroscience class, you probably learned that they're stored in our synapses, in the connections between our neurons. The basic idea is that, whenever we have an experience, the neurons involved fire together in time, and the synaptic connections between them get stronger. In this way, our memories for those experiences become minutely etched...
info_outlineSome call it the "psychedelic renaissance." In the last decade or so, interest in psychedelic drugs has surged—and not just among Silicon Valley types and psychiatrists and neuroscientists. It's also surged among a stereotypically soberer crowd: academic philosophers. The reasons are clear. With their varied and sometimes transformative effects, psychedelics raise ethical questions, epistemological questions, metaphysical questions, questions about the nature of experience and the nature of the mind.
My guest today is Dr. Chris Letheby. Chris is a philosopher of cognitive science at the University of Western Australia and the author of the 2021 book, Philosophy of Psychedelics.
Here, Chris and I talk about the so-called classic psychedelics—LSD, psilocybin, ayahuasca, and others—and how interest in them has gone through three distinct waves. We discuss the effects that these substances seem to have, in particular their capacity to treat certain psychiatric conditions and their tendency to induce "mystical-like" experiences. We consider the idea that psychedelics might serve as agents of moral enhancement. And we dig into the psychological and neural mechanisms by which psychedelics seem to have their diverse—and often salutary—effects. Along the way, we talk about ontological shock, comforting delusions, brain plasticity, unselfing, microdosing, placebo effects and adverse effects, physicalism and idealism, the REBUS model, environmental virtues, plant consciousness, meditation, and much more.
Maybe this is obvious but this episode is not just for the seasoned psychonauts out there. Whatever your personal experience with these substances, they offer a distinctive window into the mind—a new way of grappling with big questions. Perhaps this much is also obvious but we're not encouraging or endorsing the use of psychedelics here—just offering a little fuel for your intellectual fires!
Alright friends, on to my conversation w/ Dr. Chris Letheby. Enjoy!
A transcript of this episode is available here.
Notes and links
4:00 – For a brief historical overview of research into psychedelics, see this paper.
8:30 – For work by an early trailblazer in the philosophy of psychedelics, see Thomas Metzinger’s Being No One.
12:30 – For our earlier episode on the psychology and philosophy of visual illusions, see here.
18:00 – For a history of the concept of “set and setting,” see here.
19:00 – A 2024 review of “adverse events” in classic psychedelics.
26:00 – A blog post on the history of the term “psychedelic.”
27:00 – A recent review and meta-analysis of the use of psychedelic therapy for depressive symptoms.
31:00 – On mystical experience see Walter Stace’s classic work, Mysticism and Philosophy. On the measurement of mystical-type experiences, see, e.g., Walter Pahnke’s paper here.
36:00 – On the idea of “psychoplastogens,” see here.
39:00 – See our earlier audio essay on placebo effects.
41:00 – For the study using Ritalin as an active placebo, see here.
44:00 – Michael Pollan’s book on psychedelics is here.
48:00 – On the idea of “idealism,” see here.
50:30 – For the 2021 study on psychedelics’ capacity to alter metaphysical beliefs, see here.
54:00 – For Dr. Letheby and collaborators’ paper about the “mysticism wars,” see here.
1:02:00 – For a popular article on the possibility that psychedelics reduce fear of death, see here.
1:03:00 – For Dr. Letheby’s paper on psychedelics and the fear of death, see here.
1:11:00 – The phrase “comforting delusion” comes from an article by Michael Pollan.
1:15:00 – For the “REBUS model,” see here.
1:20:00 – On the idea that psychedelics could serve as agents of moral enhancement, see the paper by Brian Earp here.
1:21:00 – For Dr. Letheby’s paper on psychedelics and environmental virtues, see here. For his paper on psychedelics and forgiveness, see here.
1:23:00 – On the subfield of “virtue ethics,” see here. On the virtue of “living in place,” see the paper by Nin Kirkham here.
1:28:00 – For the New Yorker article, by Matthew Hutson, on how psychedelics led him to see trees as smart, see here. For the study, led by Sandeep Nayak, on psychedelics leading people to expand their attributions of consciousness, see here.
1:32:00 – For a first paper by Dr. Letheby on the comparison between meditation and psychedelics, see here.
Recommendations
Psychedelic Experience, Aidan Lyon
Varieties of Psychedelic Experience, Robert Masters & Jean Houston
The Antipodes of the Mind, Benny Shanon
Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala.
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